Apparatus for synthesizing nano particles, and method for synthesizing the nano particles using the same

ABSTRACT

Disclosed herein is an apparatus for synthesizing nano particles. The apparatus for synthesizing nano particles is configured to include: a plasma generator that generates plasma; a recovery device that recovers the synthesized nano particles; and a cooler that is disposed between the plasma generator and the recovery device and includes a cooling path where the nano particles are synthesized, while material supplied from the plasma generator is cooled, wherein the cooling path is set to have lower cooling temperatures for each section as going to the moving direction of the nano particles.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of Korean Patent Application No.10-2010-0009118, filed on Feb. 1, 2010, entitled “Apparatus ForSynthesizing Nano Particles, And Method For Synthesizing The NanoParticles Using The Same”, which is hereby incorporated by reference inits entirety into this application.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to an apparatus for synthesizing nanoparticles and a method for synthesizing the nano particles using thesame, and more particularly, to an apparatus for effectivelysynthesizing nano particles having a relatively large size and a methodfor synthesizing the nano particles using the same.

2. Description of the Related Art

Recently, a high temperature plasma technology has been adopted forsynthesizing ceramic or metal powders. For example, nano particles usedas a material for a ceramic substrate such as a low temperature co-firedceramic (LTCC), a high temperature co-fired ceramic (HTCC), etc. can besynthesized by a mechanical grinding method, a sol-gel method, a spraypyrolysis, a combustion synthesis, and a high temperature plasmasynthesis. However, recently, other syntheses have gradually beenreplaced by the high temperature plasma synthesis.

A nano particle synthesis technology using a general high temperatureplasma technology exposes precursors to a high temperature atmospheregenerated due to an induced electric field and dielectric breakdown ofgas and then passes the precursors vaporized by the high temperatureatmosphere through the gas flow having a relatively low temperature.Therefore, the precursors are rapidly cooled, thereby synthesizing nanoparticles in powder form.

However, the nano particle synthesis technology using the hightemperature plasma described above has a limitation in forming nanoparticles having a large size. For example, the manner to rapidly coolthe vaporized precursors leads to a relatively short period of areaction time taken in synthesizing nano particles having a sufficientsize, thereby having a difficulty in forming nano particles having alarge size. In particular, a high temperature plasma synthesis apparatuscurrently used has a difficulty in stably forming spherical nanoparticles having a diameter of 100 nm or more due to technicallimitations.

Further, with the nano particle synthesis technology using the generalhigh temperature plasma, the synthesized nano particles are deposited onthe inner walls of the synthesis apparatus, thereby causing a phenomenonthat the inside of the apparatus is polluted. The pollution phenomenonof the apparatus described above is concentrated on a period where theprecursors are rapidly cooled. If the pollution of the apparatus isaccumulated, synthesis efficiency of the nano particles is deteriorated.

SUMMARY OF THE INVENTION

The present invention has been made in an effort to provide an apparatusfor effectively synthesizing nano particles having a large size and amethod for synthesizing the nano particles using the same. For example,one object of the present invention is to provide an apparatus forstably synthesizing nano particles having a diameter of at least 100 nmor more and a method for synthesizing the nano particles using the same.

The present invention has been also made in an effort to provide anapparatus for synthesizing nano particles that prevents the inside ofthe apparatus from being polluted as the synthesized nano particles aredeposited at the inner walls of the apparatus during the synthesizingprocess of the nano particles, and a method for synthesizing the nanoparticles using the same.

An exemplary embodiment of the present invention provides an apparatusfor synthesizing nano particles including: a plasma generator thatgenerates plasma; a recovery device that recovers the synthesized nanoparticles; and a cooler that is disposed between the plasma generatorand the recovery device and includes a cooling path where the nanoparticles are synthesized, while material supplied from the plasmagenerator is cooled, wherein the cooling path is set to have lowercooling temperatures for each section as going to the moving directionof the nano particles.

The cross-section of the cooling path may be increased as going to themoving direction of the nano particles.

The cooler may include a ceramic tube having a structure where thecross-section thereof is increased as going to the moving direction ofthe nano particles.

The cooler may include ring-shaped cooling plates stacked along themoving direction of the nano particles, and the cooling plates may beprovided to have larger central opening diameters as going to the movingdirection of the nano particles.

Injection holes of which injection angle is controlled so that coolinggas is injected to the inner walls of the cooling path may be providedbetween the cooling plates and the cooler may include: a first cooinggas supply line that supplies first cooling gas to the injection holeswhich are relatively close to the plasma generator among the injectionholes; and a second cooling gas supply line that supplies second coolinggas having a lower temperature than the first cooling gas to theinjection holes which are relatively far from the plasma generator amongthe injection holes.

The apparatus for synthesizing nano particles may further include adeceleration gas supplier that is disposed on the opposite side of theplasma generator based on the cooler and injects gas to the cooling pathin a direction opposite to the moving direction of the nano particles.

The plasma generator, the cooler, and the deceleration gas supplier maybe disposed on the same line in a row, and the recovery device may bedisposed at one side of the cooler.

Another embodiment of the present invention provides an apparatus forsynthesizing nano particles including: a synthesizing part that passesprecursors through a plasma generating space where an plasma atmosphereis made to synthesize nano particles; and a recovering part thatrecovers the synthesized nano particles, wherein the synthesizing partincludes: a plasma generator that has the plasma generating space; acooler that has a cooling path where the nano particles are synthesized;and a deceleration gas supplier that supplies deceleration gas fordecelerating the moving velocity of the nano particles to the coolingpath, and the recovering part includes: a recovery pipe that isconnected to the side walls of the cooler; and a recovery chamber thatis connected to the recovery pipe, wherein the plasma generator, thecooler, and the gas supplier are sequentially disposed along a firstline, and the recovery pipe is disposed at one side of the cooler alonga second line perpendicular to the first line.

The cooling path may have lower cooling temperatures as going to thedeceleration gas supplier.

The cross-section of the cooling path may be increased as going to thedeceleration gas supplier.

The cooler may include: a first cooler that is disposed to be close tothe plasma generator and a second cooler that is disposed to be far fromthe plasma generator compared to the first cooler, wherein the coolingtemperature of the first cooler may be higher than the coolingtemperature of the second cooler.

The cooler may include: a first cooler that is disposed to be close tothe plasma generator and a second cooler that is disposed to be far fromthe plasma generator compared to the first cooler, wherein the coolingpath in the first cooler may have a smaller cross-section than thecooling path in the second cooler.

Yet another embodiment of the present invention provides a method forsynthesizing nano particles including: moving material in a plasmagenerating space in a first direction; synthesizing nano particles bycooling the material moved along the first direction; and recovering thesynthesized nano particles, wherein the synthesizing the nano particlesmay be performed by cooling the material at gradually lower temperaturesduring the moving thereof in the first direction.

The synthesizing the nano particles may further include decelerating themoving velocity of the material.

The decelerating the moving velocity of the material may be performed byinjecting cooling gas to the nano particles moved in the first directionin a second direction opposite to the first direction.

The decelerating the moving velocity of the material may be performed byincreasing the cross-section of the cooling path where the nanoparticles are synthesized as going to the first direction.

The synthesizing the nano particles may further include injectingcooling gas to the inner walls of the cooing path where the nanoparticles are synthesized along the first direction.

The recovering the nano particles may be performed after changing themoving direction of the nano particles moved in the cooling path in thefirst direction to a third direction perpendicular to the firstdirection.

Yet another embodiment of the present invention provides a method forsynthesizing nano particles including: forming nano particles by coolingprecursors while the precursors are moved in a plasma generating spacewhere a plasma atmosphere is made in a first direction, the cooling ofthe precursors being made at gradually lower temperatures as going tothe first direction.

The cooling the precursors may further include decelerating the movingvelocity of the precursors, wherein the decelerating the moving velocityof the precursors may be performed by supplying inert gas to theprecursors in a second direction opposite to the first direction.

The cooling the precursors may further include decelerating the movingvelocity of the precursors, wherein the decelerating the moving velocityof the precursors may be performed by increasing the cross-section ofthe cooling path where the nano particles are synthesized as going tothe first direction.

The cooling the precursors may be performed by supplying cooling gashaving lower temperatures as going to the first direction to the insideof the cooling path where the nano particles are synthesized.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram showing an apparatus for synthesizing nano particlesaccording to an embodiment of the present invention; and

FIG. 2 is a diagram showing a process for synthesizing nano particlesaccording to an embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Various advantages and features of the present invention and methodsaccomplishing thereof will become apparent from the followingdescription of embodiments with reference to the accompanying drawings.However, the present invention may be modified in many different formsand it should not be limited to the embodiments set forth herein.Rather, these embodiments are provided so that this disclosure will bethorough and complete, and will fully convey the scope of the inventionto those skilled in the art. Like reference numerals denote likeelements throughout the specification.

Terms used in the present specification are for explaining theembodiments rather than limiting the present invention. Unlessexplicitly described to the contrary, a singular form includes a pluralform in the present specification. The word “comprise” and variationssuch as “comprises” or “comprising,” will be understood to imply theinclusion of stated constituents, steps, operations and/or elements butnot the exclusion of any other constituents, steps, operations and/orelements.

Hereinafter, an apparatus for synthesizing nano particles and a methodfor synthesizing the nano particles using the same according toexemplary embodiments of the present invention will be described indetail with reference to the accompanying drawings.

FIG. 1 is a diagram showing an apparatus for synthesizing nano particlesaccording to an embodiment of the present invention, and FIG. 2 is adiagram showing a process for synthesizing nano particles of theapparatus for synthesizing nano particles of FIG. 1.

Referring to FIG. 1, an apparatus 100 for synthesizing nano particlesaccording to an exemplary embodiment of the present invention may beconfigured to include a synthesizing part 101 and a recovering part 102.The synthesizing part 101 may include a plasma generator 110, a cooler120, and a deceleration gas supplier 130, and the recovering part 102may include a recovery device 140. The plasma generator 110, the cooler120, and the deceleration gas supplier 130 may be arranged on a firstline 10 in a row. To the contrary, the recovery device 140 may bearranged on a second line 20 perpendicular to the first line 10 from oneside of the cooler 120. Therefore, the components 110, 120, 130, and 140of the apparatus 100 for synthesizing the nano particles may generallybe formed in an ‘L’-letter or a ‘T’-letter. Herein, the first line 10 isa perpendicular line that runs up and down, such that the plasmagenerator 110, the cooler 120, and the deceleration gas supplier 130 maybe vertically arranged.

The plasma generator 110 may provide a plasma generating space a thatforms a high temperature plasma atmosphere at the time of synthesizingthe nano particles. For example, the plasma generator 110 may include aplasma torch 112, a power supply 114, and a supply line 116. The plasmatorch 112 may be configured to generate plasma flame in the plasmagenerating space a. The power supply 114 may be a high frequency powersupply. As another example, the power supply 114 may also be a DC powersupply. The fluid supply line 116 can supply various sorts of fluids tothe plasma generating space a. For example, the fluid supply line 116may include a material supply line 116 a, a central gas supply line 116b, and a carrier gas supply line 116 c. In addition, the fluid supplyline 116 may further include a sheath gas supply line (not shown) thatsupplies sheath gas preventing the material from being deposited on theinner walls of the apparatus 100.

The cooler 120 can cool the material moved from the plasma generator110. For example, the cooler 120 may include a first cooler 122 and asecond cooler 124. The first cooler 122 and the second cooler 124 mayhave a cooling path 121 through which the fluid moves inside thereof.The cooling path 121 may have a longitudinal direction parallel to thefirst line 10. The cooling path 121 may be a space where the materialmoves in the first direction X1 and further be a space where thematerial is cooled and the nano particles are synthesized.

The first cooler 122 may be disposed to be close to the plasma generator110 compared to the second cooler 124. The first cooler 122 may includea ceramic tube 122 a and a ceramic insulator 122 b that surrounds theceramic tube 122 a. The second cooler 124 may include a plurality ofcooling plates 124 a. Each of the cooling plates 124 a may have a ringshape where the center thereof is opened. In addition, the coolingplates 124 a may have a structure where they are stacked in the firstdirection X1, for example, an up and down direction. Injection holes 126that inject predetermined cooling gas may be provided between thecooling plates 124 a. The injection holes 126 can inject the cooling gassupplied from the cooling gas supply line 125 to the inside of thecooling path 121. Herein, the injection angle of the injection holes 126can be controlled so that the cooling gas is injected to the inner wallsof the cooling path 121. Therefore, the cooling gas can prevent the nanoparticles synthesized within the cooling path 121 during thesynthesizing process of the nano particles from being deposited on theinner walls of the cooling path 121.

Meanwhile, the first cooler 122 and the second cooler 124 may be set tohave different cooling temperature. For example, the first cooler 122may be set to have a higher cooling temperature than the second cooler124. In addition, each of the first and second coolers 122 and 124 mayalso be constituted to be cooled at lower cooling temperatures for eachsection as going to the first direction X1, For example, the ceramictube 122 a of the first cooler 122 may be set to have lower coolingtemperature for each section as going to the first direction X1, To thisend, the first cooler 122 may include a plurality of ceramic heaters andin this case, it may be constituted so that the ceramic heaters set tohave a low heating temperature as going to the first direction X1 arearranged. Further, the second cooler 124 may be constituted so that thecooling gas set to have a low cooling temperature as going to the firstdirection X1 is injected. For example, the injection holes 124 b arevertically provided in plural, wherein the injection holes 124 b may bedisposed to inject the cooling gas at lower temperatures as going to thefirst direction X1. To this end, the cooling gas supply line 125includes a first cooling gas supply line 125 a that supplies the coolinggas to first injection holes 126 a disposed at a relatively higherposition and a second cooling gas supply line 125 b that supplies thecooling gas to second injection holes 126 b disposed at a lower positionthan the first injection holes 126 a, wherein the first cooling gassupply line 125 a can supply the cooling gas having a higher temperaturethan the second cooling gas supply line 125 b.

Further, the first cooler 122 and the second cooler 124 may beconstituted so that the cross-section of the cooling path 121 isincreased as going to the first direction X1. To this end, the ceramictube 122 a of the first cooler 122 may be constituted so that thecross-section thereof is increased as going to the first direction X1.Moreover, the cooling plates 124 a having different opening diametersare constituted to be vertically stacked, wherein the cooling plates 124a having a larger opening diameter as going to the first direction X1are disposed. Therefore, any one of the first cooler 122 and the secondcooler 124 may constitute the cooling path 121 having a structure wherethe cross-section thereof is increased as going to the first direction.

The deceleration gas supplier 130 can supply gas (herein, decelerationgas) that reduces moving velocity of the material and the nano particlesto the cooling path 121. For example, the deceleration gas supplier 130may include a supply port 132 and a deceleration gas supply line 134connected to the supply port 132. The supply port 132 may be disposed onthe opposite side of the plasma generator 110 based on the cooler 120.Therefore, the deceleration gas supplied from the deceleration gassupply line 134 can be injected to the cooling path 121 in a seconddirection X2 opposite to the first direction X1 by the supply port 132.

The recovery device 140 can recover the synthesized nano particles. Forexample, the recovery device 140 may include a recovery pipe 142 and arecovery chamber 144 connected to the recovery pipe 142. One end of therecovery pipe 142 may be connected to the side wall of the cooler 120and the other end thereof may be connected to the recovery chamber 144.The recovery chamber 144 may generally be disposed at one side of thecooler 120. Therefore, the nano particles that moves within the cooler120 in the first direction X1 can be recovered into the recovery chamber144 by the recovery pipe 142 after the moving direction thereof ischanged into a third direction Y perpendicular to the first directionX1.

As described above, the apparatus 100 for synthesizing nano particlesaccording an exemplary embodiment of the present invention includes thecooler 120 that cools the material for synthesizing the nano particles,wherein the cooler 120 may have the first and second coolers 122 and 124that are constituted having a lower cooling temperature for each sectionas going to the moving direction of the material. Therefore, theapparatus 100 for synthesizing nano particles according an exemplaryembodiment of the present invention may have a structure where thecooling temperature of the material becomes gradually lower as going tothe first direction X1 at the time of synthesizing the nano particles toprevent the material from being quickly frozen.

The apparatus 100 for synthesizing nano particles according an exemplaryembodiment of the present invention may include the first and secondcoolers 122 and 124 having a structure where the cross-section thereofis increased as going to the first direction X1. Therefore, the movingvelocity of the nano particles is decelerated during the moving processin the cooler 120, such that the apparatus 100 for synthesizing nanoparticles 100 can have a structure to increase the residence time of thematerial within the cooling path 121.

Further, the apparatus 100 for synthesizing nano particles according anexemplary embodiment of the present invention may include thedeceleration gas supplier 130 that supplies the deceleration gas to thecooler 120 in the second direction X2 opposite to the moving directionof the nano particles. Therefore, the apparatus 100 for synthesizingnano particles can have a structure to increase the residence time ofthe material within the cooling path 121 by decreasing the movingvelocity of the nano particles that move within the cooler 120 at thetime of synthesizing the nano particles.

Continuously, a method for synthesizing nano particles using anapparatus 100 for synthesizing nano particles having the structure asdescribed above will be described in detail. Herein, the overlappeddescription of the apparatus 100 for synthesizing nano particles asdescribed above may be omitted or simplified.

Referring to FIGS. 1 and 2, the power supply 116 can apply apredetermined high frequency power to the plasma torch 112. And, thecentral gas supply line 116 b of the fluid supply line 116 can supplycentral gas 30 to the plasma generating space a. As for the central gas30, argon (Ar) gas may be used. The central gas 30 is activated by theplasma torch 112, such that plasma flame P can be generated in theplasma generating space a. And, the material supply line 116 a and thecarrier gas supply line 116 c of the fluid supply line 116 can supplymaterial 40 and carrier gas 50 to the plasma generating space a,respectively, through the plasma torch 112. The material 40 may beprecursors of the nano particles 70 to be synthesized. The material 40can effectively move in the cooling path 121 of the cooler 120 in thefirst direction X1 by the carrier gas 50. Further, the deceleration gassupply line 134 of the deceleration gas supplier 130 can supplydeceleration gas 60 to the supply port 132. The deceleration gas 60supplied through the supply port 132 can move in the cooling path 121 inthe second direction X2.

The material 40 is cooled, in order, by the first and second coolers 122and 124 during the moving process in the cooling path 121 of the cooler120, such that the material can be synthesized into the nano particles70. Herein, the first and second coolers 122 and 124 can cool the coolpath 121 at lower cooling temperatures for each section as going to thefirst direction X1, For example, the ceramic tube 122 a of the firstcooler 122 may be constituted so that the cooling temperature thereoflowers as going to the first direction X1. Further, the first coolinggas supply line 125 a of the second cooler 124 can supply first coolinggas 80 to the first injection holes 126 a disposed at a relativelyhigher position and the second cooling gas supply line 125 b thereof cansupply second cooling gas 90 having a lower temperature than the firstcooling gas 80 to the second injection holes 126 b. Therefore, thematerial 40 can be cooled at gradually lower temperatures for eachsection during the moving process in the cooling path 121. Therefore,the probability of the material to be synthesized into the nanoparticles 70 having a larger size is increased by preventing thematerial 40 from being quickly frozen in the cooling path 121, such thatthe nano particles 70 having a large size can be synthesized.

Further, the cooling path 121 may be provided in a structure where thecross-section thereof is increased as going to the first direction X1.In this case, the moving velocity of the material 40 can be deceleratedduring the moving process in the cooling path 121. In addition, thedeceleration of the moving velocity of the material 40 can also be madeby the deceleration gas 60 as described above. As described above, themoving velocity of the material 40 that moves in the cooling path 121 isdecelerated to increase the residence time of the material 40 in thecooling path 121, thereby making it possible to increase the probabilityto be synthesized into the nano particles 70 having a larger size. Thesynthesized nano particle 70 is generally formed in power form, whereinit may have a spherical shape. At this time, the nano particle 70synthesized in the manner as described above may have a diameter of atleast 100 nm or more.

The nano particles 70 can be discharged from the synthesizing part 101and be introduced into the recovering part 102 through the recovery pipe142. Herein, the recovering part 102 is disposed at one side of thecooler 120 of the synthesizing part 101, such that the nano particles 70can be recovered into the recovery chamber 144 after the movingdirection thereof is changed into a third direction Y generallyperpendicular to the first direction X1. In this case, the movingvelocity of the material 40 can be decelerated compared to the casewhere the recovering part 102 and the synthesizing part 101 are disposedin a row along the first line 10, such that the material 40 can besynthesized into the nano particles 70 having a larger size.

Meanwhile, as described above, the apparatus 100 for synthesizing nanoparticles prevents the material 40 from being quickly frozen in thecooling path 121, thereby making it possible to prevent the material 40from being deposited on the inner walls of the cooling path 121. Forexample, there may be generated a phenomenon that the internalconstitution of the apparatus 10 is polluted by the material 40. Such apollution phenomenon may be concentrated on the region where thematerial 40 is quickly frozen. However, as described above, the presentinvention prevents the material 40 from being quickly frozen in thecooling path 121, thereby making it possible to the inner walls of thecooling path 121 from being polluted.

As described above, the method for synthesizing the nano particles usingthe apparuats 100 for synthesizing nano particles according to anexemplary embodiment of the present invention gradually cools thematerial 40 during the moving process of the material 40 along thecooling path 121 where the nano particles 70 are synthesized, such thatthe material 40 can be prevented from being quickly frozen. Therefore,the method for synthesizing the nano particles according to the presentinvention allows the time consuming in synthesizing the material 40 inthe cooling path 121 to be sufficient, such that the material 40 can besynthesized into the nano particles 70 having a larger size.

Further, the method for synthesizing nano particles according to anexemplary embodiment of the present invention can decelerate the movingvelocity of the material 40 during the moving process of the material 40along the cooling path 121 where the nano particles 70 are synthesized.Therefore, the method for synthesizing the nano particles according tothe present invention increases the residence time of the material 40 inthe cooling path 121, such that the material 40 can be synthesized intothe nano particles 70 having a larger size.

The apparatus for synthesizing nano particles according to the presentinvention includes the cooler that cools material for synthesizing nanoparticles, wherein the cooler can be constituted to have lower coolingtemperatures as going to the moving direction of the material.Therefore, the apparatus for synthesizing nano particles according tothe present invention can have a structure where the material isgradually cooled at the time of synthesizing the nano particles toprevent the material from being quickly frozen (quenched), such that thematerial can be synthesized into nano particles having a larger size.

Further, the apparatus for synthesizing nano particles according to thepresent invention can have a structure where the moving velocity of thematerial can be decelerated during the moving of the material along thecooling path where the nano particles are synthesized. Therefore, theapparatus for synthesizing nano particles according to the presentinvention can have a structure where the probability to synthesize nanoparticles having a larger size is increased by increasing the residencetime of the material in the cooling path.

The method for synthesizing nano particles according to the presentinvention gradually cools the material during the moving of the materialalong the cooling path where the nano particles are synthesized, suchthat the material can be prevented from being quickly frozen. Therefore,the method for synthesizing the nano particles according to the presentinvention allows the time consuming in synthesizing the material in thecooling path to be sufficient, such that the material can be synthesizedinto the nano particles having a larger size.

Further, the method for synthesizing the nano particles according to thepresent invention can decelerate the moving velocity of the materialduring the moving of the material along the cooling path where the nanoparticles are synthesized. Therefore, the method for synthesizing nanoparticles according to the present invention increases the residencetime of the material in the cooling path, such that the material can besynthesized into the nano particles having a larger size.

The present invention has been described in connection with what ispresently considered to be practical exemplary embodiments. Although theexemplary embodiments of the present invention have been described, thepresent invention may be also used in various other combinations,modifications and environments. In other words, the present inventionmay be changed or modified within the range of concept of the inventiondisclosed in the specification, the range equivalent to the disclosureand/or the range of the technology or knowledge in the field to whichthe present invention pertains. The exemplary embodiments describedabove have been provided to explain the best state in carrying out thepresent invention. Therefore, they may be carried out in other statesknown to the field to which the present invention pertains in usingother inventions such as the present invention and also be modified invarious forms required in specific application fields and usages of theinvention. Therefore, it is to be understood that the invention is notlimited to the disclosed embodiments, but, on the contrary, is intendedto cover various modifications and equivalent arrangements includedwithin the spirit and scope of the appended claims.

1. An apparatus for synthesizing nano particles, comprising: a plasmagenerator that generates plasma; a recovery device that recovers thesynthesized nano particles; and a cooler that is disposed between theplasma generator and the recovery device and includes a cooling pathwhere the nano particles are synthesized, while material supplied fromthe plasma generator is cooled, wherein the cooling path is set to havelower cooling temperatures for each section as going to the movingdirection of the nano particles.
 2. The apparatus for synthesizing nanoparticles according to claim 1, wherein the cross-section of the coolingpath is increased as going to the moving direction of the nanoparticles.
 3. The apparatus for synthesizing nano particles according toclaim 2, wherein the cooler includes a ceramic tube having a structurewhere the cross-section thereof is increased as going to the movingdirection of the nano particles.
 4. The apparatus for synthesizing nanoparticles according to claim 2, wherein the cooler includes ring-shapedcooling plates stacked along the moving direction of the nano particles,and the cooling plates are provided to have larger central openingdiameters as going to the moving direction of the nano particles.
 5. Theapparatus for synthesizing nano particles according to claim 4, whereininjection holes of which injection angle is controlled so that coolinggas is injected to the inner walls of the cooling path are providedbetween the cooling plates, and the cooler includes: a first cooing gassupply line that supplies first cooling gas to the injection holes whichare relatively close to the plasma generator among the injection holes;and a second cooling gas supply line that supplies second cooling gashaving a lower temperature than the first cooling gas to the injectionholes which are relatively far from the plasma generator among theinjection holes.
 6. The apparatus for synthesizing nano particlesaccording to claim 1, further comprising: a deceleration gas supplierthat is disposed on the opposite side of the plasma generator based onthe cooler and injects gas to the cooling path in a direction oppositeto the moving direction of the nano particles.
 7. The apparatus forsynthesizing nano particles according to claim 6, wherein the plasmagenerator, the cooler, and the deceleration gas supplier are disposed onthe same line in a row, and the recovery device is disposed at one sideof the cooler.
 8. An apparatus for synthesizing nano particles,comprising: a synthesizing part that passes precursors through a plasmagenerating space where an plasma atmosphere is made to synthesize nanoparticles; and a recovering part that recovers the synthesized nanoparticles, wherein the synthesizing part includes: a plasma generatorthat has the plasma generating space; a cooler that has a cooling pathwhere the nano particles are synthesized; and a deceleration gassupplier that supplies deceleration gas for decelerating the movingvelocity of the nano particles to the cooling path, and the recoveringpart includes: a recovery pipe that is connected to the side walls ofthe cooler; and a recovery chamber that is connected to the recoverypipe, wherein the plasma generator, the cooler, and the gas supplier aresequentially disposed along a first line, and the recovery pipe isdisposed at one side of the cooler along a second line perpendicular tothe first line.
 9. The apparatus for synthesizing nano particlesaccording to claim 8, wherein the cooling path has lower coolingtemperatures as going to the deceleration gas supplier.
 10. Theapparatus for synthesizing nano particles according to claim 8, whereinthe cross-section of the cooling path is increased as going to thedeceleration gas supplier.
 11. The apparatus for synthesizing nanoparticles according to claim 8, wherein the cooler includes: a firstcooler that is disposed to be close to the plasma generator; and asecond cooler that is disposed to be far from the plasma generatorcompared to the first cooler, wherein the cooling temperature of thefirst cooler may be higher than the cooling temperature of the secondcooler.
 12. The apparatus for synthesizing nano particles according toclaim 8, wherein the cooler includes: a first cooler that is disposed tobe close to the plasma generator; and a second cooler that is disposedto be far from the plasma generator compared to the first cooler,wherein the cooling path in the first cooler may have a smallercross-section than the cooling path in the second cooler.
 13. A methodfor synthesizing nano particles, comprising: moving material in a plasmagenerating space in a first direction; and synthesizing nano particlesby cooling the material moved along the first direction, wherein thesynthesizing the nano particles may be performed by cooling the materialat gradually lower temperatures during the moving thereof in the firstdirection.
 14. The method for synthesizing nano particles according toclaim 13, wherein the synthesizing the nano particles further includesdecelerating the moving velocity of the material.
 15. The method forsynthesizing nano particles according to claim 14, wherein thesynthesizing the decelerating the moving velocity of the material isperformed by injecting cooling gas to the nano particles moved in thefirst direction in a second direction opposite to the first direction.16. The method for synthesizing nano particles according to claim 14,wherein the decelerating the moving velocity of the material isperformed by increasing the cross-section of the cooling path where thenano particles are synthesized as going to the first direction.
 17. Themethod for synthesizing nano particles according to claim 13, whereinthe synthesizing the nano particles further includes injecting coolinggas to the inner walls of the cooing path where the nano particles aresynthesized along the first direction.
 18. The method for synthesizingnano particles according to claim 13, further comprising: recovering thesynthesized nano particles, wherein the recovering the synthesized nanoparticles is performed after changing the moving direction of the nanoparticles moved in the cooling path in the first direction to a thirddirection perpendicular to the first direction.
 19. A method forsynthesizing nano particles, comprising: cooling precursors and formingnano particles, while the precursors are moved in a plasma generatingspace where a plasma atmosphere is made in a first direction, thecooling the precursors being made at gradually lower temperatures asgoing to the first direction.
 20. The method for synthesizing nanoparticles according to claim 19, wherein the cooling the precursorsfurther includes decelerating the moving velocity of the precursors,wherein the decelerating the moving velocity of the precursors isperformed by supplying inert gas to the precursors in a second directionopposite to the first direction.
 21. The method for synthesizing nanoparticles according to claim 19, wherein the cooling the precursorsfurther includes decelerating the moving velocity of the precursors,wherein the decelerating the moving velocity of the precursors isperformed by increasing the cross-section of the cooling path where thenano particles are synthesized as going to the first direction.
 22. Themethod for synthesizing nano particles according to claim 19, whereinthe cooling the precursors is performed by supplying cooling gas havinglower temperatures as going to the first direction to the inside of thecooling path where the nano particles are synthesized.